IPv6 subnet calculator

IPv6 CIDR range for fd66::/48

Calculate the network address, final address, mask, and exact address capacity of any IPv6 CIDR prefix.

Example: 2606:4700::/32

Host bits are normalized to the network address before the range is calculated.

CIDR calculation

Network details for fd66::/48

The prefix identifies a network with 80 host bits. Every address from the first address through the last address belongs to this range.

CIDR prefix

fd66::/48

Network mask

ffff:ffff:ffff::

Prefix length

/48

Host bits

80

First address

fd66::

Last address

fd66::ffff:ffff:ffff:ffff:ffff

Total addresses

1208925819614629174706176

Total addresses (human readable)

2^80 addresses (1,208,925,819,614,629,174,706,176; about 1.2 septillion)

How this range is calculated

  1. 1The /48 prefix keeps the first 48 network bits fixed.
  2. 2Setting all 80 host bits to zero produces fd66::.
  3. 3Setting those host bits to one produces fd66::ffff:ffff:ffff:ffff:ffff.

Network address

The normalized prefix base

CIDR notation describes a network, not a single host. If an address with host bits set is entered, this calculator normalizes it to the network base before calculating the range.

Expanded network address

fd66:0000:0000:0000:0000:0000:0000:0000

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